A dataset composed of multiangular spectral libraries and auxiliary data at tree, leaf, needle, and bark level for three common European tree species

Aarne Hovi; Petri R Forsström; Giulia Ghielmetti; Michael E Schaepman; Miina Rautiainen

doi:10.1016/j.dib.2021.106820

A dataset composed of multiangular spectral libraries and auxiliary data at tree, leaf, needle, and bark level for three common European tree species

Data Brief. 2021 Jan 30:35:106820. doi: 10.1016/j.dib.2021.106820. eCollection 2021 Apr.

Authors

Aarne Hovi¹, Petri R Forsström¹, Giulia Ghielmetti², Michael E Schaepman², Miina Rautiainen^{1

3}

Affiliations

¹ Department of Built Environment, Aalto University, School of Engineering, P.O. Box 14100, FI-00076 Aalto, Finland.
² Department of Geography, Remote Sensing Laboratories, University of Zürich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
³ Department of Electronics and Nanoengineering, Aalto University, School of Electrical Engineering, P.O. Box 15500, FI-00076 Aalto, Finland.

Abstract

This article describes a dataset of multiangular scattering properties of small trees (height = 0.38-0.7 m) at visible, near-infrared, and shortwave-infrared wavelengths (350-2500 nm), and provides supporting auxiliary data that comprise leaf, needle, and bark spectra, and structural characteristics of the trees. Multiangular spectra were measured for 18 trees belonging to three common European tree species: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst), and sessile oak (Quercus petraea (Matt.) Liebl.). The measurements were performed in 47 different view angles across a hemisphere, using a laboratory goniometer and a non-imaging spectrometer. Leaf and needle spectra were measured for each tree, using a non-imaging spectrometer coupled to an integrating sphere. Bark spectra were measured for one sample tree per species. In addition, leaf and needle fresh mass, surface area of leaves, needles, and woody parts, silhouette area, and spherically averaged silhouette to total area ratio (STAR) for each tree were measured or derived from the measurements. The data are useful for modeling the shortwave reflectance characteristics of small trees and potentially forests, and thus benefit climate modeling or interpretation of remote sensing data.

Keywords: BRDF; Forest; Goniometer; Multiangular; Reflectance; Satellite; Transmittance; Tree.